Cherry Puzzler

While traipsing about various habitats (sandy or rocky, open or shady) along Spier Falls Road this week, I found three species of small wild cherry trees in bloom.  Two were native: Prunus susquehanae (Appalachian Cherry) and Prunus pensylvanica (Fire Cherry).  One, Prunus tomentosa (Nanking Cherry), was not, but it was definitely growing wild, far from anyone's garden. The flowers all look pretty much alike, with five white petals and a single stamen surrounded by multiple pistils.  Read on, to learn how I managed to distinguish each species.

Appalachian Cherry (Prunus susquehanae)

Appalachian Cherry was the easiest to ID, since it was the only cherry that grew no higher than maybe 18 inches from the ground, in a thicket of many plants, rather than as a single small tree. Although there's not much about Appalachian Cherry flowers to distinguish them from other species of cherry blossoms, the leaves are unique to this rather uncommon species. Unlike those of other cherries, they narrow toward the base, and they are not toothed below the middle (see the photo below, which better illustrates this trait). This cherry was growing in a sandy-soiled powerline clearcut, with full exposure to the sun. Very fragrant! And also noisy, buzzing with bees! 

Fire Cherry (Prunus pensylvanica)

Prunus pensylvanica is the most common of the small cherry trees around here, since I see it blooming now along many roadsides, as was this one. It was partly shaded by surrounding woods, though. It's a small tree, maybe 8-10 feet tall, with the flower clusters marching in a row along the twigs, each twig sporting a terminal cluster of tapering serrated leaves. Its most distinguishing feature is the reddish color of the flowering branches, a feature that's obvious in the above photo. This cherry has multiple vernacular names: Fire, Bird, or Pin. I call it Fire Cherry to remind me of those red twigs. And also because it is known to populate burned-over sites quite quickly. 

Nanking Cherry (Prunus tomentosa)

I needed help from some pro botanists to decipher the name of this small tree, the Nanking Cherry (Prunus tomentosa). I sure could not find it in my guides to North American trees, because it's an introduced ornamental species that somehow made it from manicured gardens to thrive on some rugged mountainous cliffs and quarries along the Hudson River. Unlike the other cherries in question here, the flowers are sessile to the twigs, not borne on long slender pedicels. And boy, are those twigs fuzzy! As are the leaves. This trait is called "tomentose" in botanical jargon, so hence the scientific name. I found 10 of these cherry trees scattered around an old quarry that was mined way back in the 19th Century. I wonder how they got there. Perhaps they are remnants from ornamental gardens that surrounded the hotels and cabins built back then to house the workers who quarried the mountainside for rock to build the nearby Spier Falls Dam on the Hudson River. Yes, not native, but I was glad to find them. So pretty! And a fun botanical puzzle.